Numbers 29:38

and one goat for a sin-offering; beside the continual burnt offering, and his meat-offering, and his drink-offering. The special sacrifices of this festival, which stamped it as a feast of the greatest joy, thus consisted in double the number of rams and lambs for each of the seven days, and in a total of seventy bullocks, the number being distributed to begin with thirteen and to end with seven. All this set the Festival of Tabernacles apart in the year as one on which the hearts of the people were filled with the greatest joy and gratitude, just as all the other ceremonies expressed the same thought. Leviticus 23:34; Leviticus 23:39. The eighth day, as the conclusion of the festival cycle, was placed on a level with the other festivals.